River water environment improvement and comprehensive treatment system and construction method thereof

The invention relates to a comprehensive improvement system for river water environment and a construction method thereof, and belongs to the technical field of hydraulic engineering construction. The system comprises a first ecological pond, a first subsurface wetland, a second subsurface wetland and a second ecological pond, the outer sides of the first and second subsurface flow wetlands are water inlet channels, the inner sides of the first and second subsurface flow wetlands are water outlet channels, and the first and second subsurface flow wet enclosing walls adopt water outlet lattice walls. River water on the upstream of the riverway sequentially passes through the first ecological pond, the first subsurface wetland, the second subsurface wetland and the second ecological pond to be subjected to multiple filtration and then enters the downstream of the riverway. According to the system, the two ecological ponds and the two subsurface flow wetlands are arranged, so that the whole system has multiple f